1. Field of the Invention
The invention relates to a manufacturing method of a bag body, for example a contact portion that is a member that forms a tip portion of a grasping apparatus, and that is formed by filling a granulated substance into a bag-shaped member. A case is described below in which the bag body is applied to a contact portion that is a member that forms a tip portion of a grasping apparatus. However, the range of application of the bag body is not limited thereto.
2. Description of Related Art
A grasping apparatus for grasping a workpiece is developed that can reliably grasp workpieces of various shapes without replacing a tip portion or the like. Also, in this type of grasping apparatus, a reliable grasping state is able to be ensured by deforming a contact portion that is a portion that directly contacts the workpiece so that it conforms to the shape of the workpiece. The contact portion is able to take on two opposite forms, i.e., one in which the shape of the contact portion is able to flexibly deform and another in which the shape of the contact portion is firmly maintained, with a single member.
The contact portion provided with this kind of grasping apparatus that is used is such that a granular substance such as synthetic mullite is filled inside of a bag-shaped member made of rubber. Also, Japanese Patent Application Publication No. 2005-54490 (JP 2005-54490 A), for example, describes technology related to a manufacturing method of a bag-shaped member made of rubber.
The bag-shaped member made of rubber that is used for the contact portion of the grasping apparatus is used with the inside evacuated, so in order to be able to reliably ensure a vacuum, an open portion for providing a cap or the like may be made as small as possible. In order to manufacture a bag body for a contact portion having such a small open portion, manufacturing is typically performed by a method that involves vulcanize-bonding using a press apparatus or the like as described in JP 2005-54490 A. With this kind of manufacturing method, the finishing work and the like of the bag-shaped member must be performed manually by a skilled worker, so the manufacturing cost of the bag-shaped member and the contact portion that is formed using this bag-shaped member increases, and mass production is difficult. Also, in order to use the rubber bag-shaped member that is manufactured according to the technology described in JP 2005-54490 A as a contact portion, a step of filling a granular substance of synthetic mullite or the like into the bag-shaped member must be provided separately.